According to the New York Post, 38-year-old Simon Smith of the United Kingdom was discovered wearing a mask over his head with his body inside a cupboard.

A former funeral director, he is believed to have been killed following an "extremely dangerous" game of "breath play." Categorized as autoerotic asphyxiation, the act is when a person intentionally restricts oxygen to the brain for the purposes of sexual arousal.

Authorities got involved in the investigation on May 26 when Smith did not appear at his job at a library in Milford Haven. They went to his home in Fishguard and found him in the cupboard in a black leather mask. The coroner, Mark Layton, says that Smith did not want to kill himself, and it was an accident, reports New York Post. "There is nothing to suggest that this was an attempt at suicide, Smith’s history of depression doesn’t appear to be a factor in his death,” he said. Layton explained that the cause of death from attempted “sexual asphyxia” and is catagorized as "misadventure.”

As Slateshares, autoerotic asphyxiation (or AEA) is often performed when the person, usually male, puts a rope or belt around his neck and and attaches the other end to a door or pipe. He then lowers himself into a controlled suspension. When oxygen levels decrease, lightheadedness occurs that some find increases sexual pleasure.

The first recorded case of AEA death was in 1791. Since then, the death of pop culture figures including singer Michael Hutchence and actor David Carradine has been pointed to AEA. The act is often reported as a suicide so it's difficult to pinpoint AEA cases always. The FBI estimates that the act accounts for approximately 500 to 1,000 deaths a year.